Table : US Characteristics of Normal Kidneys

Feature Normal Characteristic Size Length: Adult: 9-13 cm (decreases with age) Male: 11.4 cm median length Female: 10.9 cm median length Volume: (length × width × height × 0.52) Adult: Male: range: 109-194 mL 151 mL median volume Female: range: 91-151 mL 122 mL median volume Parenchymal thickness: Normal >10 mm Echogenicity of cortex Adult: renal parenchyma echogenicity equal to, or slightly less than, normal liver parenchyma Neonate: renal parenchyma echogenicity usually greater than normal liver parenchyma Echogenicity of medulla Adult: slightly less than renal cortex Neonate: much less than renal cortex Surface Smooth, well-defined, slightly lobulated with V-shaped notches between lobes Peak systolic velocity in main renal artery Normal <180> Renal/aortic velocity ratio Normal <3.5 Resistive index–intrarenal arteries and main renal artery Adult: Normal <0.70>0.70 Systolic rise time (time to early systolic peak) in main renal artery